using System;

​

namespace ConsoleApp1

{

    class Program

    {

        static void Main(string[] args) { Console.WriteLine(FactorialPrimarySum(8)); }

        public static int SumN(int n) //1#

        {

            if (n == 1)

            {

                return 1;

            }

            return n + SumN(n - 1);

        }

        public static int SumArray(int[] data, int i)

        {

            if (i == 0)

            {

                return data[0];

            }

            return i + SumArray(data, i - 1);

        }

        public static int MaxInArray(int[] data, int i)

        {

            if (i == 0)

            {

                return data[i];

            }

            return Math.Max(data[i], MaxInArray(data, i - 1));

        }

        public static int FactorialSum(int n)//2#

        {

            if (n == 1)

            {

                return 1;

            }

            return n *= FactorialSum(n - 1);

        }

        public static int FactorialPrimarySum(int n)//3#

        {

            if (n == 1)

            {

                return 1;

            }

            if (n % 2 == 0)

            {

                return  FactorialPrimarySum(n - 1);

            }

            else

            {

                return n + FactorialPrimarySum(n - 1);

            }

        }

        public static int //4#

    }

}

​